This application relates to a bypass directional control valve for use in a pumping system.
Pumping systems are known, and utilized in any number of applications. One application is a gear pump delivering fuel to accessories on a gas turbine engine, such as to a Fuel/Oil Cooler (FOC).
In known systems, a pressure regulating valve is positioned downstream of the gear pump, and operates to bypass a portion of the pumped fluid back to an inlet for the gear pump.
A bypass directional control valve receives the bypass fluid downstream of the pressure regulating valve, and directs the bypass flow into two paths. A first path may be delivered through a heat exchanger, such as a fuel oil cooler, and the second path may be delivered without passing through such a cooler. The bypass directional control valve receives a control pressure signal to move to distinct positions to control the amount of fluid delivered to the two paths, respectively.
Bypass directional control valves in the prior art have resulted in undesirably high pressure losses.